GSFC (preliminary) IDS submission (2003-2007) for ITRF2008.
The submission consists of 256 SINEX files from 2003-2007.

The submission is based on DORIS processing of Four satellites  (ENVISAT, SPOT2, SPOT4, SPOT5) for 2003-2007.

We have followed the new standards that we described to you in a  previous email.  The submission differs in the following ways  from the files you received from GSFC in October.

1. We use the DORIS supplied offset corrections for all satellites.
 (previously we used the GEODYN internal attitude model and the
   CNES supplied offsets).
2. We use a new version of GEODYN (0812).
3. We apply a new gravity model: grvfld.eigen.gl04s1.ierscs21
  (vs ggm02c applied before)
4. We apply a different set of OLOAD information based
   on the GOT4.7 (Richard Ray) tide model.
 (The previous submission used GOT00)
5. We apply ocean tides from the GOT4.7 vs GOT00 previously.
6. We apply ECMWF-6hr Atmospheric gravity (vs NCEP-6h before)  Previously also we allowed for interpolation between 6hr time  steps. Since the GEODYN group informed us this temporal  interpolation was not fully validated, we now *do not* apply  the temporal interoplation when ATGRAV is applied  (this now matches identically the procedures used in the
    GSFC GRACE processing)
7. We now apply the ATGRAV correction for the C21/S21 terms.
  Due to a coding standard probably not  documented
   this was not applied in previous versions of GEODYN.
8. Apriori station coordinates are now from DPOD2005 vs
    a combination of ITRF2005 and a solution provided by IGN.

9. Please note that at present 2003-2004 do not yet include  TOPEx. We are working on this, and this should be ready by  Friday - but we did not wish to delay the submission  any longer-- we wished to validate the computations (orbits)  with some external (SLR+DORIS) comparisons to make sure  everything is nominal.

In addition the SOLVE to SINEX transcription program has been  updated since the last submission.  The program now  correctly maps the apriori station coordinates to the epoch  of the SINEX file (not the case before). No eccentricity correction  is applied and the coordinates all refer to the ARP (Antenna  Reference Point).

The submission presently does not include the SINEX files for the following  dates  gsc 03012  (2003-01-12)  gsc 03075  (2003-03-16)  gsc 05247  (2005-09-04)  gsc 06001  (2006-01-01)